1. Field of the Invention
This invention relates generally to surgical clips and more particularly to polymeric ligating clips having improved retention
2. Antecedents of the Invention
Numerous surgical procedures require cutting blood vessels and ducts which might require temporary or permanent ligation. Ligation of vessels or other tissues can be performed by closing the vessel with a ligating clip, or by suturing the vessel with surgical thread. Ligation by suturing required complex and difficult time-consuming manipulations of a needle and suture material. Such complex manipulations were often difficult to perform and diverted attention to the surgical procedure itself. Accordingly, the employment of ligating clips, which are relatively easy and quick to apply has grown dramatically.
Hemostatic and aneurysm clips have been used in surgery for ligating blood vessels or other tissues to stop the flow of blood. Such clips have also been used for interrupting or occluding ducts and vessels in particular surgeries. Ligating clips have been applied to the vessel or other tissue by using a surgical clip applies, ligating clip applies, or hemostatic clip applier.
While metallic ligating clips have been employed, metallic clips have been found to interfere with the imaging techniques such as computer tomography and magnetic resonance imaging. To overcome such limitations, biocompatible polymers have been increasingly used for ligating clips. Unlike metallic clips, which are usually symmetric, polymeric clips are usually asymmetric.
These polymeric ligating clips generally comprise a pair of curved legs joined at their proximal ends with an integral hinge. The distal end of one leg terminates in a hook into which the distal end of the other leg securely fits to lock the legs together. The distal ends of the legs of the clips disclosed in U.S. Pat. No. 4,834,096 include lateral bosses that are engaged by jaws of a clip applier which is employed to close the clip around the tissue to be ligated, and to latch or lock the clip in the closed condition. In operation, the jaws of the clip applier are actuated to force the bosses toward one another. This causes the legs to pivot inwardly about the hinge, thereby deflecting the hook of the one leg to allow reception therein of the distal end of the other leg.
Ligating clips must have a sufficient degree of clamping force and retention on a vessel or duct, so as not to move relative to the vessel or duct when applied, while also preserving tissue integrity and minimizing tissue damage. Among the previous approaches at attaining the appropriate retention were spaced ribs extending transversely across the inner face of each leg as disclosed in U.S. Pat. No. 5,062,846, a collapsible flexible rib extending longitudinally along the inner face of a leg, as disclosed in U.S. Pat. No. 9,445,820 and a rib extending longitudinally along the inner face of a leg which seats in a groove formed in the inner face of the other leg, as disclosed in Publication No. 2005/0165423 A1.
There remained a need however; to provide a ligating clip capable of being firmly secured to the tissue or vessel walls without slippage with a minimum level of damage to tissue or vessel walls.